//===--- ARMEHABI.h - ARM Exception Handling ABI ----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// This source file is part of the polarphp.org open source project
//
// Copyright (c) 2017 - 2019 polarphp software foundation
// Copyright (c) 2017 - 2019 zzu_softboy <zzu_softboy@163.com>
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://polarphp.org/LICENSE.txt for license information
// See https://polarphp.org/CONTRIBUTORS.txt for the list of polarphp project authors
//
// Created by polarboy on 2018/10/17.

//===----------------------------------------------------------------------===//
//
// This file defines the constants for the ARM unwind opcodes and exception
// handling table entry kinds.
//
// The enumerations and constants in this file reflect the ARM EHABI
// Specification as published by ARM.
//
// Exception Handling ABI for the ARM Architecture r2.09 - November 30, 2012
//
// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0038a/IHI0038A_ehabi.pdf
//
//===----------------------------------------------------------------------===//

#ifndef POLARPHP_UTILS_ARM_EHABI_H
#define POLARPHP_UTILS_ARM_EHABI_H

namespace polar {
namespace arm {
namespace ehabi {
/// ARM exception handling table entry kinds
enum EHTEntryKind
{
   EHT_GENERIC = 0x00,
   EHT_COMPACT = 0x80
};

enum
{
   /// Special entry for the function never unwind
   EXIDX_CANTUNWIND = 0x1
};

/// ARM-defined frame unwinding opcodes
enum UnwindOpcodes
{
   // Format: 00xxxxxx
   // Purpose: vsp = vsp + ((x << 2) + 4)
   UNWIND_OPCODE_INC_VSP = 0x00,

   // Format: 01xxxxxx
   // Purpose: vsp = vsp - ((x << 2) + 4)
   UNWIND_OPCODE_DEC_VSP = 0x40,

   // Format: 10000000 00000000
   // Purpose: refuse to unwind
   UNWIND_OPCODE_REFUSE = 0x8000,

   // Format: 1000xxxx xxxxxxxx
   // Purpose: pop r[15:12], r[11:4]
   // Constraint: x != 0
   UNWIND_OPCODE_POP_REG_MASK_R4 = 0x8000,

   // Format: 1001xxxx
   // Purpose: vsp = r[x]
   // Constraint: x != 13 && x != 15
   UNWIND_OPCODE_SET_VSP = 0x90,

   // Format: 10100xxx
   // Purpose: pop r[(4+x):4]
   UNWIND_OPCODE_POP_REG_RANGE_R4 = 0xa0,

   // Format: 10101xxx
   // Purpose: pop r14, r[(4+x):4]
   UNWIND_OPCODE_POP_REG_RANGE_R4_R14 = 0xa8,

   // Format: 10110000
   // Purpose: finish
   UNWIND_OPCODE_FINISH = 0xb0,

   // Format: 10110001 0000xxxx
   // Purpose: pop r[3:0]
   // Constraint: x != 0
   UNWIND_OPCODE_POP_REG_MASK = 0xb100,

   // Format: 10110010 x(uleb128)
   // Purpose: vsp = vsp + ((x << 2) + 0x204)
   UNWIND_OPCODE_INC_VSP_ULEB128 = 0xb2,

   // Format: 10110011 xxxxyyyy
   // Purpose: pop d[(x+y):x]
   UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDX = 0xb300,

   // Format: 10111xxx
   // Purpose: pop d[(8+x):8]
   UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDX_D8 = 0xb8,

   // Format: 11000xxx
   // Purpose: pop wR[(10+x):10]
   UNWIND_OPCODE_POP_WIRELESS_MMX_REG_RANGE_WR10 = 0xc0,

   // Format: 11000110 xxxxyyyy
   // Purpose: pop wR[(x+y):x]
   UNWIND_OPCODE_POP_WIRELESS_MMX_REG_RANGE = 0xc600,

   // Format: 11000111 0000xxxx
   // Purpose: pop wCGR[3:0]
   // Constraint: x != 0
   UNWIND_OPCODE_POP_WIRELESS_MMX_REG_MASK = 0xc700,

   // Format: 11001000 xxxxyyyy
   // Purpose: pop d[(16+x+y):(16+x)]
   UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDD_D16 = 0xc800,

   // Format: 11001001 xxxxyyyy
   // Purpose: pop d[(x+y):x]
   UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDD = 0xc900,

   // Format: 11010xxx
   // Purpose: pop d[(8+x):8]
   UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDD_D8 = 0xd0
};

/// ARM-defined Personality Routine Index
enum PersonalityRoutineIndex
{
   // To make the exception handling table become more compact, ARM defined
   // several personality routines in EHABI.  There are 3 different
   // personality routines in ARM EHABI currently.  It is possible to have 16
   // pre-defined personality routines at most.
   AEABI_UNWIND_CPP_PR0 = 0,
   AEABI_UNWIND_CPP_PR1 = 1,
   AEABI_UNWIND_CPP_PR2 = 2,

   NUM_PERSONALITY_INDEX
};

} // ehabi
} // arm
} // ehabi

#endif // POLARPHP_UTILS_ARM_EHABI_H
